| Electronics > Repair |
| Repair Help for APC UPS BR1500G - F06 error (FIXED!!) |
| << < (5/13) > >> |
| fmashockie:
--- Quote from: RLP on August 30, 2023, 04:45:57 am ---. This is kind of familiar to me because I had a similar thing happen when I was working on a UPS once. In my case it was the main 12V power supply of the unit, which went up to about 25V! It turned out to be because I'd damaged a resistor in the feedback loop of a switching regulator, while soldering a probe to it to measure the voltage, and it was a complete distraction from the main problem I was troubleshooting on the UPS. I had to replace a few ICs and fix the power supply - but it was alright in the end. --- End quote --- All too similar to what I'm dealing with here! :-DD Thank you so much for your help RLP. Unfortunately, I don't see any obvious shorts yet. But definitely will be taking a closer look! --- Quote from: Vovk_Z on August 29, 2023, 08:34:08 am ---I'm not sure 3V3 rail is ok. Are you sure you are doing measuring right? It mustn't have such a pulsations I guess. Are you sure you have replaced all electrolytic caps? --- End quote --- My apologies Vovk. It turns out I was not measuring the 3.3V rail in that second oscilloscope photo. I did however find out why the controller was not turning on. The DC/DC converter (MC34063EC) was not switching. I measured no voltage on the emitter switch pin 2. Not sure why the converter is not switching tho. When it is not switching, it does not provide voltage to an LM317T and a LP2950 (KY5033). The KY5033 is the regulator for the 3.3V rail. I supplied 3.3V to the output and the display came on. I decided to desolder the MC34063 to see if the hiccup on the 24V rail would stop, but it did not (see attached photo). So still more troubleshooting left to do. Thanks for everyone's input! |
| Vovk_Z:
--- Quote from: fmashockie on August 30, 2023, 05:34:38 am --- I did however find out why the controller was not turning on. The DC/DC converter (MC34063EC) was not switching. I measured no voltage on the emitter switch pin 2. Not sure why the converter is not switching tho. When it is not switching, it does not provide voltage to an LM317T and a LP2950 (KY5033). --- End quote --- I totally lost what are you doing and what is happening. There was only one problem at first - a problem with a relay. But now you have more problems? :-// I don't know what to say because the more you are into it the more problems you have. :) |
| coromonadalix:
and without a proper schematics, at some point you only do guessing ... and create maybe more problems than needed on some 1500 models i did saw some mentions about smt alu caps creating more noise on the supply lines ... and one in a feedback loop i had one of theses who almost blown up the battery cells, had problems getting them out ??? trashed the unit |
| fmashockie:
Yep it seems that could definitely be the case here. No schematic for newer APC models like this one - I've looked everywhere. At this point, my hopes of fixing it are not high. I'm just hoping to learn from the experience and troubleshooting. I'm self-taught with this stuff and mostly learn by doing. I definitely appreciate everyone's help though! |
| fmashockie:
Still haven't quit on this thing yet! So as I said, for a bit there I thought I had killed this thing for good. But I found out the reason why the LCD controller was not powering up - I must have inadvertently fried the DC/DC converter. I replaced it and it powered up fine. But I was back at square one - still had the F06 error... Just like a few of you speculated, I decided to take a closer look at all the relays after I replaced them. I tested each one individually during different operation modes of the UPS - (battery power only, mains power only, and battery+mains right before F06 fault takes place). I found that only one relay was not switching at all - Relay RY14. So I started looking more closely at this relay. There's a digital NPN transistor (PDTD113ZT) and a 31V zener connected to the coil. The base of the transistor connects to the microcontroller at a GPIO pin. (I attached a schematic I drew of this portion of the circuit below). Now that I understood the circuit, I decided to see what would happen if I injected ~1VDC at the base of the transistor, hoping it would switch on the relay. I did this right before the F06 error would normally happen, and it switched the relay on... No fault occurred!! So it is indeed this RY14 not switching that is the cause of the issue!! Now I measured the output of the microcontroller GPIO this transistor base connects to. At no point in time did I measure a voltage > 0VDC. So the micro is not sending a signal to switch on the relay. Does anybody have any thoughts why? Could it be anything else besides the micro being faulty? Thoughts for further testing/troubleshooting?? I greatly appreciate everyone's help so far. Look forward to hearing your thoughts!! Here's a video I did explaining where I am at with this thing and the test I did. It's a bit long, but it might help better understand the issue. Thanks everyone!! |
| Navigation |
| Message Index |
| Next page |
| Previous page |